There are many materials in need of protection from atmospheric moisture, particularly in the context of specialty goods manufactured by the pharmaceutical, chemical, computer, electronics, military, and food industries. In particular, water vapor in the air is known to have harmful effects on numerous specialty goods, and in the context of frequently opened and resealed products, these harmful effects are often amplified. Accordingly, and in an effort to reduce the damage caused by ambient water vapor, a desiccant typically accompanies those specialty goods in need of moisture protection. For example, pouched or otherwise packaged desiccants routinely accompany specialty goods as part of the product packaging, or in some cases as an integral component of the good itself.
In these types of situations, the accompanying desiccant is able to absorb and hold moisture that would otherwise be in the atmosphere contacting the specialty good (i.e., in the surrounding volume of air) to thereby prevent or reduce the harmful effects that may be caused by ambient water vapor. Although desiccants are of great commercial value, there are, surprisingly, only three major types of desiccants currently available, namely; (1) montmorillonite clay; (2) silica gel; and (3) molecular sieve.
As is known to those skilled in the art, montmorillonite clay is a naturally-occurring calcium aluminum silicate type of hydrous clay; furthermore, it is a non-hazardous material which is typically ground, processed, and bagged prior to use as a desiccant. Similarly, silica gel is a form of sponge-like silica manufactured from sodium silicate and sulfuric acid, and like montmorillonite clay, it is a non-hazardous material which is typically bagged prior to use as a desiccant. Finally, molecular sieve is a manufactured crystalline version of zeolite containing a network of uniform pores and empty cavities, and it too is a non-hazardous material which is typically bagged prior to use as a desiccant.
A common attribute of fresh desiccant is its ability to absorb and hold water. For example, in an atmosphere having 100% humidity, the three commercially available desiccants mentioned above are able to absorb water in an amount ranging from approximately 28% to 40% of their respective masses. Once, however, the desiccant has absorbed its holding capacity of water, it is no longer effective and must be replenished. Although the desiccant may be recharged by removal of the absorbed moisture by, for example, dry heating, this practice is generally not employed because it is considered cost prohibitive; that is, it is usually much cheaper to simply replace the spent desiccant with fresh desiccant.
A significant factor contributing to the high costs associated with desiccant replacement is that the three commercially available desiccants are, as noted above, typically bagged prior to use. In others words, granules of montmorillonite clay, silica gel, or molecular sieve (in selected amounts) are usually placed within a porous pouch or receptacle prior to their accompaniment with the specialty good in need of moisture protection. This practice of desiccant bagging increases the costs of spent desiccant recharging significantly because the bag is generally removed prior to dry heating (thereby making it more economical to simply replace the spent desiccant with new desiccant). A related problem with desiccant bagging is that the resulting bagged desiccant may have a tendency to shift or move about during transportation of the specialty good; such movement may have undesirable consequences.
Accordingly, there is a need in the art for new compositions useful as desiccants, as well as for methods of making and using such new compositions. The present invention fulfills these needs, and provides for further related advantages as disclosed herein.